Pseudotuberculosis in sheep as a concern of veterinary public health

The Relevance of Caseous Lymphadenitis as a Cause of Culling in Adult Sheep

Simple Summary

Caseous lymphadenitis is a widespread disease, which has been noticed in most sheep farming countries, causing important economic losses. This disease produces emaciation and weakness in the animals and has to be considered in the differential diagnosis of the so-called ‘’thin ewe syndrome’’, especially when sheep are affected by the visceral presentation of the disease. The present study analysed the prevalence of the disease in the Ebro valley area in Spain and its implication as a cause of culling in adult sheep.

Abstract

Four hundred and ninety-eight culled sheep received at the Ruminant Clinical Service of the Veterinary Faculty of Zaragoza, Spain, were examined in life and after humanitarian sacrifice in order to reach the final diagnosis of the cause of culling and to evaluate the presence of caseous lymphadenitis (CLA) lesions. One hundred and forty-seven of the 498 studied animals (29.52%) showed CLA compatible lesions that were subsequently confirmed by Corynebacterium pseudotuberculosis isolation. One hundred and seven of the 147 CLA affected animals presenting the visceral clinical form of the disease (72.79%), while only 32 animals were affected by the superficial form (21.77%). In addition, eight animals were found to be affected in both the visceral and the superficial presentations (5.44%). Eighty-four of the 147 CLA-affected animals (57.14%) did not show any concurrent disease, considering, in this case, CLA the main cause of culling (84/498: 16.87%). In the superficial presentation, the retropharyngeal lymph node, as a sole lesion, was the most frequently affected (13/32: 40.63%). Further, in the visceral form of the disease, 85.06% of the affected animals had the lesions located in the respiratory system (91/107: 85.06%). CLA was revealed as an important cause of culling in sheep production.

Multiple factors correlating with wing malformations in the population of Parnassius apollo (Lepidoptera: Papilionidae) restituted from a low number of individuals: A mini review

The Apollo butterfly, Parnassius apollo (Linnaeus), was common in Europe over 100 years ago, but currently it is considered as near threatened. Different conservation programs have promoted the persistence of this species; however, it is still endangered. An example of such programs was the action devoted to reestablish the Apollo butterfly population in Pieniny National Park (Poland) from only 20-30 individuals which had survived till the last decade of the 20th century. This reintroduction has been successful; however, unexpected developmental problems appeared. Butterflies with deformed or reduced wings became frequent in the population living in the natural habitat, and particularly among those reared under seminatural conditions (in the same environment, but fenced by a net). Until recently, reasons for these malformations remained unknown. However, reports published during last months indicated that there are genetic, biochemical, and microbiological factors contributing to this phenomenon. In the malformed individuals, lesions in the wingless gene and dysfunctions of laccase 1 and 2 were found to be significantly more frequent than in normal insects. A large fraction of butterflies with deformed or reduced wings was devoid of the prokaryotic symbiont Wolbachia, which was present in most normal individuals. Moreover, Yersinia pseudotuberculosis (Pfeiffer) Smith and Thal, and Serratia sp., bacteria pathogenic to insects, were detected in the biological material from both normal and malformed butterflies from this population. These findings are summarized and discussed in this review, in the light of conservation of insects and restitution of their populations from a low number of individuals.